Contamination of the ground, water and air in the environment has become a serious problem in recent times. One source of such contamination is in the spillage of fluids, particularly petroleum products at storage facilities for such products. For instance, storage tanks at gasoline filling stations are located underground and have a fill-pipe which extends upward from the tank to ground level so that the unloading hose of a tank truck can be connected to the open end of the fill-pipe in order to fill the storage tank. Spillage of gasoline is almost unavoidable during this process and various devices for containing the gasoline thus spilled have been devised in order to prevent it from saturating the ground and seeping into underground water sources or from flowing on the surface into streams and rivers.
United States patents granted on such devices and similar systems include the following:
U.S. Pat. No. 4,278,115 Briles PA1 U.S. Pat. No. 4,457,349 Vazin PA1 U.S. Pat. No. 4,520,852 Klein PA1 U.S. Pat. No. 4,527,708 Dundas et al PA1 U.S. Pat. No. 4,615,362 Hartman et al
In general, containment is achieved by installing a container or manhole below ground level around the upper end of the fill-pipe so that any gasoline spilled is trapped within the container and then removed therefrom, either back into the fill-pipe or into an external waste container. In some cases this spillage drains by gravity into the storage tank through drainage pipes in the bottom of the spill container. In others, a sump or accumulating tank is provided below the spill container. Still others have complicated systems of containing the spilled fluid and preventing it from vaporizing into the atmosphere, as well as limiting the amount of fluid that is spilled.
One of the problems with such spill containers now available is that they are frequently complicated and expensive to manufacture and install. Even in those devices which provide only a simple sump below the spill container, it is difficult and expensive for small gasoline station operators to install the container or to remove it for replacement or repair. Another serious problem encountered has been in maintaining the seal between the spill container and the fill-pipe in order to prevent the fluid trapped i the container from leaking into the ground. The difficulty is that frost will lift and/or tilt the spill container relative to the spill-pipe. Settlement of the ground will also cause such movement. In new tank installations even the tank itself may move enough to make the fill-pipe move within the spill container. Similarly, those systems which have a drainage line from the spill container back into the fill-pipe are subject to malfunctions and require substantial excavation around the fill-pipe simply to repair the piping below the container
It is important therefore that spill-control devices of this type be as simple, reliable and inexpensive to manufacture as possible Several specific areas where improvements in this respect have been needed are, (1) in the seal that must be made at the point where the fill-pipe enters the container in order to prevent leakage of the spilled fuel therefrom, while permitting movement of the spill container relative to the fill-pipe due to frost and soil settling, (2) in the means by which the spilled fluid is removed from the spill container and (3) in preventing water, dirt and other debris from entering the container and contaminating spilled fluid captured within the container.
It is accordingly the object of this invention to provide a pollution control device which is inexpensive to manufacture and install, requires little or no maintenance and which is dependable not only in containing fluid spilled during transfer, but also in avoiding contamination of the spilled fluid by rain water and other foreign material.